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Ahuka

Host ID: 198

I am a long-time office software geek, and also a promoter of Free Software, so LibreOffice is a natural fit for me. I also have a series on HPR called Security and Privacy, and occasionally record shows that are non-series. I am also the former Tech Track organizer for Penguicon, an event in southeast Michigan, USA. Visit one of my sites at:

In previous episodes we set the stage by examining insurance, the marketplace, competing interests, tradeoffs, and costs. With that we can now understand what Obamacare attempted to do and give a tentative evaluation of the legislation and its effects.

The Health Care Marketplace in the U.S. has 6 major partipants: Doctors, Hospitals, Insurance Companies, Employers, Government, and Individuals. Each of them has interests and incentives, and they tend to clash. How we resolve those competing interests has consequences for the systems we create.

Health care is a service, and like all services it needs to be paid for one way or another. This means making choices, and there are consequences and implications to whichever choice you make. But there is no free lunch, you have to pay.

Penguicon 2017 is a combined technology and science fiction convention in Southfield, Michigan, a suburb of Detroit, and presents over 500 hours of programming over the entire weekend. Of this, around 100 hours are open source, tech-related. In this episode I tell you about my own personal experience at Penguicon this year.

Links:

Penguicon 2017 is a combined technology and science fiction convention in Southfield, Michigan, a suburb of Detroit, and presents over 500 hours of programming over the entire weekend. Of this, around 100 hours are open source, tech-related. In this episode I give you a look at the lineup you can expect to see.

Links:

Ohio LinuxFest is an annual Linux and Open Source conference held in the fall in Columbus, Ohio, USA. This year it happened on October 7-8, and I was not only an attendee, but a speaker. This program is about my experiences there this year.

I had the opportunity to present a talk on SSL Certificates at our local LUG, the Washtenaw Linux Users Group, which uses some material from a previous HPR episode, but may be of interest to our listeners nonetheless. Because this was a lengthy presentation I have divided it into sections. This is the second section which will explore some of the problems that we have with SSL Certificates, and how we might address those problems. The first section contains our description of how SSL Certificates work.

I had the opportunity to present a talk on SSL Certificates at our local LUG, the Washtenaw Linux Users Group, which uses some material from a previous HPR episode, but may be of interest to our listeners nonetheless. Because this was a lengthy presentation I have divided it into sections. This first section explains how SSL Certificates work, and the second one will explore some of the problems that we have with SSL Certificates, and how we might address those problems. For more go to http://www.zwilnik.com/?page_id=655

Penguicon 2015 is a combined technology and science fiction convention in Southfield, Michigan, a suburb of Detroit, and presented over 500 hours of programming over the entire weekend. Of this, around 100 hours were open source, tech-related. In this episode I give you my personal diary of my experience at this great event.

Links:

I had the opportunity to present a talk on the LastPass intrusion at our local LUG, the Washtenaw Linux Users Group, which expanded on a previous HPR episode and added some additional material that I think might be of interest to our listeners. I still stand by my claim that LastPass was not seriously affected by the intrusion and is still an excellent security solution for most computer users.
For more go to http://www.zwilnik.com/?page_id=841

Links:

When you first try to login to a remote server you need to authenticate yourself, which means you have to demonstrate that you have rights to be on that server. You can do this in several ways:

Password You authenticate to the server by typing in your password. This is easy because you can generally remember your password, and it means you can easily login from any computer with that knowledge. This is still the most common authentication mechanism for SSH. It is also the least secure.

Public Key This is much more secure. It involves the creation of a key pair, of course. It is possible to use a key pair generated by PGP or GPG in the most current versions (version 2.0.13 introduced support for this). But there is a long established method using the Unix program ssh-keygen. This is very similar to generating a key pair as we discussed earlier. You run the program ssh-keygen, harvest some entropy, generate a passphrase to protect it, and so on.

We now have looked at three of the four objects that are offered to you on a new slide: Charts, Pictures, and Movies. So now it is time to take a look at Tables. You have options here, such as embedding a table from Calc or Writer, and there are times when you need that degree of power. But most of the time you can do what you need inside of Impress using its own functionality. As we saw last time with Charts, you can just click the button in the middle of a new slide and insert a Table that way, but that may not always be feasible, so you have the alternative option of going to the Insert menu and selecting Table.
For more go to http://www.ahuka.com/?page_id=1285

Links

In the last tutorial we looked at OLE objects, and saw that Charts could be brought into Impress from Calc via OLE. But you can create the Charts directly in Impress. Bear in mind that due to the modular nature of LibreOffice you will be using the same tools to do this as Calc uses: LibreOffice developers never reinvent the wheel if they can avoid it.

There is a lot to know about Charts if you are going to use them effectively, and we covered all of this in our Calc tutorials.
For more go to http://www.ahuka.com/?page_id=1291

So as we saw in the introductory tutorial, SSH uses the Client-Server model. Now, technically a server is just the machine you are connecting to, and there is no reason in principle that it could not be another desktop, a laptop, or even a telephone if it has the appropriate software. and in the previous tutorial we showed how you can easily install and set up an ssh server on your home network using another computer or a Raspberry Pi so that you can experiment with these commands. The model really reduces to you as the client, and the other machine as the server. As with all Internet connections there are standards and protocols involved. The original Telnet communicated over TCP through port 23. Because SSH was conceived as a replacement, it used the same TCP protocols, and was assigned the adjacent port number of 22.
For more go to http://www.zwilnik.com/?page_id=726

The next topic we want to cover involves something called OLE, which stands for Object Linking and Embedding. This was developed by Microsoft, but has spread to the free software world as well. What it means is that you can use data from two different programs together, and changes made in place are automatically reflected in the other place. A great example comes with spreadsheets, since you create them in a spreadsheet program like Calc, but you might want to take a table created there and put it into a slide to display.
For more go to http://www.ahuka.com/?page_id=1275

Links

One thing that Impress lets you do that can be kind of fun is to use Multimedia files in your presentations in various ways. Now, there are some interesting limitations here. First of all, any time you want sounds, whether from an audio file or as part of a movie file, you need to have the right hardware. This means a little planning ahead. In many of the places where I do presentations the video is all I have. But most modern projectors, particularly in corporate meeting rooms, have the capability of playing audio as well as video.
For more go to http://www.ahuka.com/?page_id=1271

I know we have focused a lot on using Styles to control the formatting of text, and there is a reason for that. As I have said so often, uniformity of appearance is an important part of a professional-looking presentation, and that is best done by using the Presentation and Drawing Object styles appropriately. But there is a place for all of the other tools Impress has, and I want to go over some of them now before we move on to other topics.
For more go to http://www.ahuka.com/?page_id=1262

The best way to get familiarity with the concepts we will discuss is by experimentation. I think that it is becoming more common these days for people to own more than one computer and set them up in a network. And with cheap computers like Raspberry Pi it is really easy to get started. In this tutorial I want to discuss how you can set up such a server for your experiments in ssh. I encourage you to do this even though I dont intend this series to focus on server administration. The idea is that by practising these these techniques behind a good firewall you can get some familiarity with them before you get out on the Internet where it matters. For most Linux users, at least, installing and setting up a server is really simple, and you can do it minutes.
For more go to http://www.zwilnik.com/?page_id=847

Text Boxes are considered graphical objects, actually, so they are controlled by the Drawing Object Styles. These can be a little bit confusing because they are shared among different LibreOffice modules, so some of the things you see arent really meant for Impress. For example, there are three Title styles, but none of them are meant for putting titles on slides. They are actually meant for putting titles on drawings, such as engineering drawings. If you you wanted to have a slide title but use Text boxes, you should select the Title Only slide layout. The Title would be controlled by the Title Presentation Style.
For more go to http://www.ahuka.com/?page_id=1250

We have spent several tutorials on graphics, including the Themes and the Gallery, and that is all to the good since Impress is a graphical program to some degree. But it also is a way of presenting text content, and it worth a little time to develop that further. Impress does some things with text that resemble other programs like Writer, but it also does some things differently so it is worth a moment to discuss these specifics.
For more go to http://www.ahuka.com/?page_id=1245

Links

In 1995 there was a password-sniffing attack on the network of the University of Helsinki in Finland, and this lead a researcher there, Tatu Ylönen, to create the first SSH implementation. SSH is an acronym for Secure Shell, and expresses the idea that you can securely log in and get a shell on a remote server. This was initially released as free software, but in later versions he took it proprietary. But the developers at OpenBSD decided that a free software implementation was needed, and they created OpenSSH, which is the basis for most implementations today.
For more go to http://www.zwilnik.com/?page_id=722

In the last tutorial we looked at pictures and how they can be used in Impress. But I left out one area because the tutorial was already running a bit long, and I wanted to give the Gallery and Themes the full attention they deserve. I think this is something a lot of people have missed when working with Impress, at least I have not seen these elements includes much in peoples presentations. But they are a wonderful addition to your toolkit, and well-worth some attention. Note that the Gallery is a common feature of all LibreOffice applications, and is available in applications like Writer and Calc, though there is less need for it there. It is when you get to applications like Impress and Draw that you really discover how useful it can be.
For more go to http://www.ahuka.com/?page_id=1222

Links

As we pointed out previously, Impress is inherently a graphical, and even multimedia, way of communicating. In fact, we saw in the previous tutorials that Impress and Draw share a common set of Styles that apply to both programs, and I have often seen in documentation that Impress and Draw are often mentioned in the same breath, so to speak. So it is important that we start developing an understanding of the graphical elements in Impress.
For more go to http://www.ahuka.com/?page_id=1217

The idea in this tutorial is to tie together some of the concepts developed in the previous tutorials to create a Master Page, or Template, or Slide Master. (They all mean the same thing, but within Impress they are shown on the Sidebar as Master Pages, so I will stick with that terminology here.) I say we will use some of these concepts because trying to put everything into one Master Page would create a hideous end result. And since it helps to have a definite objective in mind I have decided to create one for Hacker Public Radio, where I record these tutorials as podcasts for the Internet.
For more go to http://www.ahuka.com/?page_id=1204

In the previous tutorial we looked at Presentation Styles, and I started with them because they were mostly similar to what we already covered in Writer when we looked at Paragraph styles. But Impress is a graphical product, so we need to wrap our heads around a different set of issues here. and that brings us to Drawing Object Styles.

On June 15, LastPass disclosed that it had been hacked, and I think by now just about everyone has heard about it. I know I received questions because I have recommended LastPass often, and my advice has been to stay with them. What I want to do now is explain exactly why this was not quite the big deal it was made out to be in some quarters, and that anyone telling you to stop using password vaults is only asking you to lower your own security.

We have previously looked at Styles for Writer, and for Calc, and now it is time to look at them for Impress. You may recall from both Writer and Calc that we saw it is important to know that Styles live inside of Templates. So any time you change a Style you needed to make sure it was saved inside of a Template, and if you wanted it to be generally available in all documents or spreadsheets you needed to be sure to make the change inside the Default Template.
For more go to http://www.ahuka.com/?page_id=1125

Although my wife and I have a Cable TV subscription, I have maintained I could give it up easily because so much of what I am interested in is online anyway. For many people that might mean Netflix or Hulu, but for me it means YouTube. This is the golden age of narrow-casting, as opposed to broadcasting, because YouTube gives so many creators the opportunity to find their own audience for things that dont appeal to the masses.
For more go to http://www.palain.com/?p=243

The terms Template and Master Pages refer to the same thing, but inside the Impress application they are referred to as Master Pages, and they are accessed on the right-hand side of the page. If you as the author do not choose a specific Template to use when creating a new presentation, Impress will base the presentation on the default Template that is built in to Impress. But you can create your own default Template if you like.
For more go to http://www.ahuka.com/?page_id=1188

Penguicon 2015 is a combined technology and science fiction convention in Southfield, Michigan, a suburb of Detroit, and presented over 500 hours of programming over the entire weekend. Of this, around 100 hours were open source, tech-related. In this episode I give you my personal diary of my experience at this great event.

Having looked at the theory of building a good presentation, now we can look at the mechanics of how to build a presentation. This will take you step-by-step through the creation process and get you ready to create your own awesome presentations.
For more go to http://www.ahuka.com/?page_id=1188

Previously we looked at the issues around TrueCrypt and Heartbleed, and noted that a fundamental problem was that technologies we rely on to be safe are often developed and maintained by volunteers or people on a shoestring budget. There is now more news worth looking at in this respect, so it is time for an update.
For more go to http://www.zwilnik.com/?page_id=825

Having looked at the screen layout, now we can look at how to build a presentation by focusing on the content first, and not the eye candy. This can be done by creating an outline, or by beginning with a blank presentation. We discuss both and give some ideas on which to use in each situation.
For more go to http://www.ahuka.com/?page_id=1100

Now we can start to take a look at the actual Impress application, and we begin by looking a how the program is laid out on the screen. Knowing where to find key features is important in using the program efficiently.
For more go to http://www.ahuka.com/?page_id=1112

Penguicon 2015 is a combined technology and sicence fiction convention in Southfield, Michigan, a suburb of Detroit, and will present over 350 hours of programming over the entire weekend. Of this, around 100 hours are open source, tech-related. In this episode I try to cover the coming attractions of the weekend and maybe entice some people to come join us. It will be a great weekend.

Links:

We begin the discussion of Impress, the Presentation Graphics (i.e. slide deck) component of Libre Office. In this episode we look at some of the basic issues around presentations that you need to consider *before* you open up the software. Constructing a good presentation is not easy, and there are some good principles that the masters of the art can impart. WE discuss some of these here and provide links to good resources.
For more go to http://www.ahuka.com/?page_id=1087

I have received a very generous offer from Bernard J. Poole, a professor at the University of Pittsburgh. He has a series of LibreOffice Tutorials and has asked me to publicize that they are available free of charge to all of our LibreOffice fans on Hacker Public Radio. You can find his tutorials on his web site at http://www.pitt.edu/~poole/. He is particularly aiming his tutorials at educators who might use LibreOffice in the classroom

The last few tutorials have looked at the techniques you need to master to use Styles and Templates effectively, but putting these into practice is essential to understanding them, I believe. So it is time for us to actually built a Template that incorporates a few styles and put the whole package together. For my example, I am going to create something useful for a consultant who needs to keep track of time for billing customers.

Last time we looked at some basics about how TLS and SSL work, and saw that this is basically an application of the same technology used to encrypt e-mails. But we also noted that there are some problems with this approach. We need to recognize that in security there is never a permanent solution, and that vulnerabilities are constantly being discovered, and ideally then being fixed. Some of these may involve highly technical issues about cryptographic methods, but I think the largest category of issues is about the processes around the use of certificates.
For more go to http://www.zwilnik.com/?page_id=686

Our next topic is Cell Styles. If you are already familiar with Styles from Writer, think of Cell Styles as the equivalent of Writers Paragraph Styles. Just as a single Writer document can have a variety of Paragraph Styles applied to different paragraphs (e.g. Headings, Lists, Paragraphs), a single spreadsheet can have multiple Cell Styles. And the same arguments for using Styles also apply. If you have consistently used Cell Styles in your spreadsheet, you can update the appearance easily just by changing the Style instead of needing to go through the file looking for every cell that needs to be adjusted. And by using Styles you can apply a large number of formatting choices to many cells with just a few mouse clicks. So it really does pay to learn how to use Cell Styles.

Page Styles in LibreOffice Calc set the properties for entire sheets of your workbook file. In any given Template you can have different sheets with different Page Styles if you wish, but for any given sheet you can only have one Page Style. And dont be confused by the difference between a sheet in the file and a page when printed. One single sheet may take many physical pages to print, but it is all one sheet and it is all governed by a single Page Style.

As I said in the last tutorial, Templates can be understood as a container for a number of settings, most particularly Styles. This follows the object model, which is a lot like those Russian dolls inside of each other. The File for your spreadsheet is an object, and it contains individual Sheets which are objects. Each Sheet contains Cells which are objects. And each Cell contains various Characters which are objects, which can be used to represent numbers, formulas, addresses, labels, etc. Objects exhibit two features we always want to keep in mind. First, objects have properties that are particular to the kind of object. The properties of a file might include who the author is, where the file resides on the system, any access restrictions (like making the file password-protected), and so on.

The properties of each sheet might include things like the name of the sheet, the orientation (landscape vs. portrait), headers and footers, etc. Then the properties of the cell might include the type of cell and how
it is formatted (text, currency, general number, etc.). And finally the properties of the Character include the font family, font style, font size, and so on.

When we were looking at Writer we saw that Styles and Templates are key concepts to using any word processor. They are not quite as central in spreadsheet use, and one can be a proficient user without resort to them, but they do give you control over the appearance of your spreadsheets, and can give the sheets you create uniform appearance. We discussed these ideas in great detail in our Writer tutorials, so I am going to hope that some of that knowledge has carried over here. Still, lets get to some basic concepts:

Digital Signatures are something that is very important in understanding security on the Internet. While we have seen it in the context of personal e-mail, the applications are much broader, in particular to the use of certificates to establish communication.

Recall from our discussion of e-mail that there are two things you can do with an e-mail using PGP or GPG. First is you can encrypt the message, which you do using the public key of the recipient, and then they can decrypt the message using their private key. The other was putting a digital signature on a message. But how does that work? - For more go to http://www.zwilnik.com/?page_id=655

Ruth Suehle gave the next-to-last keynote at Ohio LinuxFest 2014 on 2014-10-25. In this talk she discusses the significance of open hardware and maker culture, and how this is something we all should participate in. Maker culture is an essential part of the free and open culture we belive in when we talk about open source. And we need to be vigilant to protect our values in the hardware space. As an example she tells us about Bre Pettis and Makerbot, which at one time were very open, but have turned aginst this value as they became more successful. In the final analysis, it is up to us to protect open hardware by voting with our dollars/euros/whatever.

You can set a Standard Filter from within the AutoFilter drop-down, or you can go there through the Data menu by selecting Data>Filter>Standard Filter. Now lets look at the question we ended the last tutorial with: How many females over the age 40 had a case in 1978. We saw we could get this by manually putting checkmarks in every age that was greater than 40 using AutoFilter, but how do we do this using Standard Filter? - For more go to http://www.ahuka.com/?page_id=897

Previously we looked at Public Key encryption, which is also called Asymmetric Encryption because it uses two different keys for the encryption and decryption. This allows us to solve one of the biggest problems in secure encrypted communication, which is key distribution. Because the public key can be freely distributed, you dont need to maintain security around the process of distributing keys. Symmetric encryption, on the other hand, relies on a shared key that is used for both encryption and decryption. An example of this is the one-time pad, where you printed up a pad of paper that contained various keys, and each one was used only once. As long as no one can get the key, it is unbreakable, but the big weakness was key distribution. How do you get the one-time pad into the hands of your correspondent? And you would need to do this with separate one-time pads for each person you needed to communicate with. These are the kinds of problems that made asymmetric encryption so popular. Finally, symmetric key crypto cannot be used to reliably create a digital signature. The reason should be clear. If I have the same secret key you used to sign a message, I can alter the message, use the shared secret key myself, and claim you sent it. - For more go to http://www.zwilnik.com/?page_id=650

Ken Starks gave the closing keynote at Ohio LinuxFest 2014 on 10/25/14. In this talk he discusses his work with the REGLUE project (formerly the Helios Project) which bulds computers to give to disadvantaged kids in Texas. And if you look there may be something like this in your town that you can help with. And if not, why not start one? This talk was recorded by Randy Noseworthy, and he asked me to post it to HPR.

The next major area of investigation for this series is how we can do data manipulation in Calc. Although Calc is not a database, it can be used for some data analysis and manipulation. When I worked for the finance department of a hospital, it was very common for the financial analysts to get a data dump from a centralized system as a CSV file, load it up in a spreadsheet, and then slice-and-dice the data to get the answers they wanted. It is not anywhere near what you can do with a good relational database and a structured query, but you can do some quick-and-dirty analysis here. - For more go to http://www.ahuka.com/?page_id=879

We spent a lot of time looking at some Financial and Statistical functions. I don't propose to go into the remaining types of function in nearly the same depth. That would draw out the series without benefit to most people. But I do want to highlight some of the functions in the other categories so that you have an idea of what is possible in Calc. Remember that if you need to know more about them Google is your friend. - For more go to http://www.ahuka.com/?page_id=875

I am the coordinator for the Tech Track at Penguicon 2015, which is a combined FOSS/Science Fiction convention held every spring in the Metro-Detroit area. The 2015 event will happen April 24-26 at the Westin Hotel in Southfield, MI. The theme for the upcoming year's event is Biotechnology and medicine, looking at how technology is affecting our health and life. But we want a lot of different talks as well, so I will be happy to accept proposals that look at things like cloud computing, security, hardware hacks, and anything else that would be of interest to geeks and hackers.

Links:

Right now for most of us the key to any security in our online life is the degree of entropy in our passwords. So what is entropy, and how does it affect our passwords?

Entropy is in general the degree of randomness or disorder in any given system. Sometimes it is very easy to assess, such as a password of 1234, which all too many people use. Because it is a simple sequence, there is no real randomness at all, and would be quickly guessed. And as we saw in the last tutorial, such passwords are quickly discovered in a dictionary attack. There are things you can do to make it less likely that your password will be cracked and used against you. - For more go to http://www.zwilnik.com/?page_id=530

Inferential statistics is what you do to say that something is likely, or that it is not due to chance, or things of the sort. It goes beyond simply describing what is in the numbers and lets you say something about what the numbers in a sample might mean for the population that generated the sample. There are several type of Inferential Statistics that I want to address in this tutorial, beginning with the idea of a confidence interval. - For more go to http://www.ahuka.com/?page_id=861

In Statistics there are generally speaking two types of analysis, broken down between Descriptive and Inferential statistics. The difference has to do what what claims you are making about the data. If you are simply stating something about the data (e.g. there were more men than women in the sample) that is descriptive. But if you make a claim that something is not likely to occur by chance, for instance, or that something is statistically significant (and both of those statements are essentially the same thing) then you are in the realm of inferential statistics. Calc has functions to do both kinds of analysis, and this tutorial will examine some of the common descriptive statistics in Calc and how they are used. - For more go to http://www.ahuka.com/?page_id=844

Today, the most common way of providing security in giving access to data or systems is through the use of passwords. Practically every online site now expects you to create an account with a password, which will let you post comments, order products, conduct business, or just post to social media. The implication is that insisting on passwords provides some level of security. Now, following on our last tutorial we should ask a few questions about just how effective this measure is, since someone posting in your name to Twitter is significantly different from someone accessing your bank account. And since the assets being protected are very different, it would be reasonable to approach the problem of security somewhat differently in these cases. But given the ubiquity of passwords as the authentication for online accounts, we need to look at the security involved. Note that I am approaching this from the standpoint of the owner of the site in question for this tutorial, and will follow up with a look at your own role in this. For more go to http://www.zwilnik.com/?page_id=640

We take a look at a number of related financial functions in this episode, and discover that they are strongly related by using the same variables over and over. We construct a Mortgage Repayment Schedule, and look again at the principles of good spreadsheet construction.

Back in 2001 there was a certain incident on September 11 that lead many people to go OMG! We are doomed! We must increase security! Do whatever it takes! And the NSA was happy to oblige. And on 7/7/05 an attack in London added to the frenzy. I think it is fair to say that these security agencies felt they were given a mandate to do anything as long as it stops the attacks, and thus was the overwhelming attack on privacy moved to a whole level higher. To be clear, security agencies are always pushing the limits, it is in their DNA. And politicians have learned that you never lose votes by insisting on stronger security and appearing tough. - For more go to http://www.zwilnik.com/?page_id=577

In this episode we review what a function is, discuss the different types of functions available in LibreOffice, discuss the concept of arguments in mathematics, and present a general process for using functions in Calc.

We have looked at e-mail encryption on both Thunderbird and G-Mail, and that is good, but in 2014 a lot of people use mobile phones and tablets for their e-mail. So it makes sense to look at how we can do this. The solution I am going explore here involves two components, the K-9 Android mail client, and APG, the Android Privacy Guard. I am going to stick to what I know, so if you are looking for help with iPhone or iPad, the best I can do is suggest that you try a Google search. On Android, while many people use Gmail, K-9 is a very popular client for people looking for a more traditional POP3 or IMAP client to handle their e-mail needs. So this should be a good solution for many people. As regards APG, I am not aware that anyone has done an audit of this program. It seems to be the most widely recommended, and is probably OK, but I am making no larger claims for it. - For more go to http://www.zwilnik.com/?page_id=602

This episode covers various editing techniques you might use, including multiple sheets, and adding, removing and hiding rows and columns. We also discuss how to navigate around a multiple sheet spreadsheet.

LibreOffice Calc, like all spreadsheets, contains a large number of cells in various rows, columns, and sheets, and navigating that can get a little tricky. As we saw previously, each cell has an address, which is marked by the column (letters) and the row (numbers), always in that order. But in fact the address can be larger because we never discussed sheets.

By default, when you create a new Calc spreadsheet you will have three sheets in it, which you see as tabs along the bottom of the screen. They will be called Sheet 1, Sheet 2, and Sheet 3 at this point. But these defaults can be changed by going to Tools–>Options–>LibreOffice Calc–>Defaults. On this screen you can decide how many sheets you want to have on a new document. While the default as it comes is three (similar to Microsoft Excel) you can change it. On my copy of Calc I changed it to 1, because most of the time I never need more than one sheet for my work. I can also change the default naming of new sheets here. Instead of each sheet being “Sheet 1″, Sheet 2″, etc. I could make it something else, like “Tab 1″, “Tab 2″. and so on. I never bother with this though, because I will always name my sheets for what they are doing in a given spreadsheet (e.g. look at what I did when I created the simple model for “What-If” analysis.) And if I need to add a sheet, I can just go to Insert–>Sheet to bring up a window to specify where the sheet should go, what it should be named, or even insert a sheet from a file . A CSV file would be a very good choice here, such as if you wanted to bring in data from a database or another spreadsheet for use in the current spreadsheet.

Two recent events have shed light on some fundamental issues in getting security in Open Source projects. One of them is a serious bug referred to as "Heartbleed", and the other is the first part of a security audit of the TrueCrypt encryption program. By looking at both of these together and doing a Lessons Learned we can draw some conclusions about what is needed to have security in Open Source projects.

Show notes: In late fall 2013 I became involved in the Penguicon
convention, which combines Open Source technology with Science Fiction to
create something that I believe to be unique. I ended up taking
responsibility for organizing the Tech Track, and we ended up with around 70
hours of programming. I recap some of the highlights of my own personal
experience of this event, both as a participant and as an organizer.

In the previous tutorial we discussed the fundamental ideas of building models and doing “What-If?” analysis. Now we need to take these ideas and put them into practice so you can see how this works. To do this I will create a simple model of savings over time. Now, I do want to be clear that this is a very over-simplified model and should not be taken as a good predictor of actual results. The idea is to illustrate the techniques involved in building a model and doing “What-If?” analysis.

So. what are the variables, parameters, assumptions, etc. that we need? I have identified these in my model:

An initial amount of money already saved. This is the starting amount you have.

This is a recording of a talk I gave at my local Linux Users Group, the Washtenaw Linux Users Group, or LUGWASH. In this talk I cover some of the theory of encryption, how to generate keys, and using this with Thunderbird, with Gmail, and on an Android phone.

The next topic is extremely important because it addresses where most beginning users of spreadsheets get into trouble. First, understand that building models and doing "What-If" analysis is fundamental to the success and widespread adoption of spreadsheets all over the world. A model can be thought of as a mathematical representation of a process of some kind. It could be financial, such as projecting my sales over the next year, or perhaps working out when my car loan will be paid off. Or it could be scientific, such as projecting out the reaction times and quantities in a chemical reaction. The only real requirement is that whatever you are modeling has to be something that can be represented using mathematical formulas of some kind.

"What-If" analysis takes this model and lets you experiment to see how how changes in different variables affect the results in your model. If I am figuring out when my car loan will be paid off, I might ask how paying an extra $20 per month against the principle would affect my results (presumably, it should lead to getting it paid off sooner if I set the model up correctly.) Or in the case of the chemical process, how would different temperatures or pressures affect the reaction times and quantities? By experimenting with different values in my model I can do this comparison easily. But only if I built the model properly in the first place.

One of the key techniques in using a spreadsheet is to master the art of fills, which lets you fill a column or a row with data without having to type in every cell individually. And this technique requires that there be a predictable pattern to the contents of each cell as you fill them. But you can do a lot with this technique, and we will want to use this when we do our first model, which will be a simple savings model.

But first we need to build the tools in our tool kit, and fills are a big one. To begin with, you can fill either rows or columns, though columns are more frequently filled using this technique. Still, it is good to know you can do either. The simplest fill begins with a cell that has some kind of contents. For example, lets say that cell B1 contains the word "Rain". If you click on the cell, you will see it highlighted with a thick black border

One of the issues in using public key encryption is ensuring you know who you are communicating with, and that you have correctly matched the owner to the key. Otherwise, your communication could be intercepted and decrypted by a third-party. The way we solve this problem is with key signing, which is often done at key signing parties. We discuss all this with Tony Bemus of the Sunday Morning Linux Review.

Since the main purpose of a spreadsheet is to perform calculations it is appropriate that we consider just how this is done.

In general, a cell of a spreadsheet can contain one of three things:

A number

Text

A formula

All calculations are done using formulas. A formula occurs whenever a cell has contents that begin with an equals sign, which is the signal to Calc that it needs to perform a calculation. For instance, if a cell contains "A3+B3", Calc would examine this, see the letters and the plus sign, and decide that the contents of the cell were a text string. After all, it cannot be a pure number with those other things there. But place an equals sign in front, so that the contents now read "=A3+B3" and Calc knows that this is formula, and will perform the calculation. And one of the best ways to interact with a cell that contains a formula is to use the Formula Bar, which normally appears just above the cells of the spreadsheet proper:

LibreOffice Calc: Cells

All spreadsheets have the same basic structure, a table of rows and columns. Columns are headed up A, B, C, and so on. After Z, the next column is AA, then AB, AC, AD, and so on. The maximum number of columns is 1024. Rows are numbered 1,2,3 and so on, and the maximum number of rows is 1024*1024, or 1,048,576. At this time I am not aware of any plans to increase these numbers, though that could change if competitive pressures make it necessary.

Where a row and column intersect, there is a cell, which is given the address of the column followed by the row, e.g. A1, but never 1A. This is very useful since you can use the contents of a cell in a calculation by simply using the cell address. For example, to add the value of cell B4 to the value in cell C3 and store it, you would write “=B4+C3″ in the cell where you want to store the sum. Learning to use cell addresses is extremely important, so get in the habit of doing this at every opportunity.

Last time we looked at how you can use GPG and Enigmail to digitally sign or encrypt messages in Thunderbird. But today many people use web-based mail, and one of the most popular is Googles Gmail. Others include Outlook.com and Yahoo, but using any of them is pretty similar. So since I have a Gmail account handy, I will use that to demonstrate encryption in web mail accounts.

The important thing you must keep in mind is that this relies on you using your GPG keys to either sign or encrypt the message before it leaves your computer, what Steve Gibson calls Pre-Interent Encryption, or PIE. The flaw in what Lavabit did (discussed in previous lesson) was to use keys that the mail provider controlled, and these keys could be (and were) demanded by the the government.. If you use your own GPG keys that you control, no provider (Google, in this case) is even capable of giving anything to the government other than a blob of random nonsense.

To do this, I will use an extension for Googles Chrome Browser called Mailvelope. This is also available for Firefox, but in my case I use Chrome to access my Gmail account., so using a Chrome extension makes sense for me. The first thing to do is go to the Chrome store, search for Mailvelope, and install it.

LibreOffice Calc: What is a Spreadsheet?

There are different ways to answer this question. Functionally, spreadsheets are a tool for mathematical calculations, but have branched out into related areas like data analysis. Some people even use them as a quick-and-dirty database tool. If you are in a financial profession of some kind you probably live in spreadsheets all day.

Spreadsheets are original “killer app”. Early examples were implemented on mainframe computers in the 1960s, but the big step was the creation of VisiCalc for the Apple II in 1979, which was then ported to the IBM PC in 1981. VisiCalc set the conventions that guided all subsequent spreadsheets, and the essential methods have not changed since then. VisiCalc was called the first killer app because people would buy the computer just to run the program, and the usefulness of spreadsheets is what promoted the initial entry of personal computers into the corporate world, with all of the change that has caused.

Now it is time to take a look at practical uses of encryption, and the number one use is for e-mail. Encrypted communication via e-mail is very desirable if you want to keep a secret. In the U.S. the current legal precedents say that any e-mail left on a server is not protected since you would have no expectation of privacy. This precedent was set many years ago when POP3 was the standard for all e-mail and people did not usually leave e-mail on a server. These days, many people use web-based e-mail or use a newer standard called IMAP which by default stores everything on the server. Perhaps you are one of these people, and thought that you had a right to expect privacy, but in the U.S. you dont, and I would expect that in many other countries the situation is no better.

There have been attempts to provide encrypted e-mail service from a service provider, but the problem here is that the provider usually has to have to the key in order to encrypt the e-mail, and if they have the key they can be compelled to give it up. Recently in the U.S. there was a case involving Ladar Levison who ran such a service called Lavabit. Lavabit encrypted mail in transit using TLS encryption, and he had the keys. When his service was used by Edward Snowden, the government came to get the keys. Now, Levison would have given them the key for Snowdens e-mail if he had been served a warrant, as he always made clear to his customers that he would obey proper legal demands. But in this case the government demanded that he turn over all of the keys for all his customers, and this was too far for Levison. He shut down his service rather than cooperate, and is a bit of a hero for that. But it illustrates that you are at the mercy of the service provider. If the government made this demand to Lavabit, you are safe in presuming they had made the same demand to other providers, and that they all cooperated with the government and said nothing to their customers. So it would be mistake to rely on 3rd party mail service providers to give you privacy. You need to control it yourself. But of course, after the last few lessons you know how to do that, and have your secure keys created. You just need to put them to use.

Other Page Layout Options

As we mentioned in beginning our look at Page Layout, you have some options other than just Page Styles and Frame Styles, useful though they are. So let’s spend a few moments looking at these other options and see how they work.

Tables

Tables can be a useful tool for more than just displaying tabular data. You can place different object in each cell of a table and so have some control over how things are laid out on the page. You could, for instance, place your sub-heads in a left-hand column, and the associated text in an adjoining column, which gives you the same effect as using the Marginalia style. And you can add pictures, charts, and other objects as well. You can even insert a table into a cell of another table to get more fine-grained control. In fact, in the days before Cascading Style Sheets and Javascript, tables were the primary way of laying out Web pages, though these days that is frowned upon, and in any case most Web pages are now created using some kind of CMS software like WordPress, or Drupal. The idea of using tables was more attractive when we realized you could turn-off the cell borders and make them invisible. Of course, in Writer documents that only works when they are printed. When opened on a computer the table borders are still visible, as indeed they would have to be for you to edit the document.

This continues our look at frames by looking at frame styles for things other than text.

LibreOffice Writer Other Frame Styles

In the previous tutorial we looked at using the frame style for text, which is not called the Text style, but the Frame style, which may be confusing. This is a very common use of frames, but there are others. To start the discussion, let’s get back to the basic concept of objects. LibreOffice is an object-oriented program and you should keep this in mind when dealing with this software.

A piece of text can be an object, and it can contain other objects (paragraphs, sentences, words, characters), or it can be contained within other objects (section, chapter, document). In the case we are looking at, a frame is an object, which contains other objects, and is in turn contained within larger objects (page, section, document). Depending on the objects being contained, the frame styles can be different, and that is what we need to look at now.

In the previous program we explained how to use the command line tools to generate encryption keys. This time we look at the GUI clients that some people may prefer. Using KGpg as an example, we can see that it does all the things we did last time on the command line.

This is the second of two programs that look at Frame properties in LibreOffice Writer. In the first program we looked at how to size and position Frames. Here we look at other things you can do, such as name your frames for linking, wrap text around frames, set the borders and backgrounds, and even add columns to the frame. This finishes the look at the Properties window and what you can do there.

This episode introduces the discussion of Frames in LibreOffice Writer by opening the Properties window and looking at the first tab, Type. Because there is so much to discuss about this tab, it is the only one we will look at in this episode. In the next episode we will wrap up the discussion of Frame properties by looking at the other tabs in this window

Links

We are given polling results constantly in news stories, and even more so when an election is near. But how accurate are these polls? What are the limitations? And what kinds of questions should you have when looking at these surveys? I will attempt to answer these questions in this podcast.

Hacker Public Radio welcomes everyone to record shows and contribute them to the network. In this show we discuss the many ways you can do that. It is very easy to contribute a show and get involved, so we encourage everyone to join in.

This program is about the new online streaming music service from Google, called Google Play Music All Access.

Like many people I enjoy listening to music, and having my music with me everywhere is important. And I have a large music collection to draw on. Trying to have everything with me at all times is a bit of a problem, though, considering how much music I have. Right now I own a number of portable MP3 players, two of which are full of music that I carry with me. My pockets can get very full that way, though, and while I like listening to tracks I own, what about finding new stuff? My MP3 players have never suggested anything to me. This is where the cloud services come in.

In this episode of our Privacy and Security series we look at the fundamentals of encryption and how it has developed over the centuries. We will also develop a basic idea of the current asymmetric public key cryptography.

In this episode of our Privacy and Security series we look at two issues. The first is why we need Privacy, and the second is whether it is practical in the 21st century. I hope to show that we do need it, and that it is both practical and surprisingly easy to do some simple things to obtain it.

In looking at the distinction between free of charge and free as in freedom, some interesting issues emerge. I argue that free of charge is often not what we should be lookiing for if we want good software options. But because I like going the long way around behind the barn to get anywhere, I start off in the Music business.

Indie and Creative Commons

Bandcamp - I just learned about this site from my friend Craig Maloney, who does the Open Metal Cast. This site has Creative Commons music from bands who want to build a relationship with their fans and sell them music. Good artists like Amanda Palmer are here.

e-Books

When it comes to books, you really are at the mercy of the individual publishers. Most music labels have finally come to accept that no DRM is the best way to go, but must book publishers are still being dragged into the 21st century kicking and screaming. But there are some good places to find e-books that respect your freedom.

Project Gutenberg - This is the granddaddy of the DRM free book sites. Project Gutenberg makes available books that are in the Public Domain, i.e., where the copyright has run out. These are mainly older books, but a lot of classics are in here. They make books available in all of the major formats.

Baen Books - This publisher specializes in the harder Science Fiction, but they really understand the new media landscape. They not only offer most of their books DRM-free and in multiple formats, but they also have the Baen Free Library, where they offer selected books free of charge. The hope is that with the first taste free, you will want to buy more. And it works. I went there to see what they had, discovered that they had the entire collected works of one of my favorite authors (James H. Schmitz) for sale, and bought the lot of them.

Tor/Forge - A major publisher in the Science Fiction and Fantasy fields, they just moved to going DRM free a few months ago. They did this because other publishers had been successful in so doing.

Angry Robot - Along with Baen, a pioneer in selling DRM-free books in the Science Fiction and Fantasy fields.

Avon Romance - A major publisher of romance novels, they just announced that they are experimenting with DRM-free ebook sales.

O'Reilly Media - The premiere publisher of technical books, they pretty get everything right. They sell e-books without DRM. When a new edition of a book you already bought comes out you can "upgrade" for a nominal fee (e.g. I upgraded my Kevin Purdy "Android" book for $1). And with older books that they think are no longer worth in print, they are removing the copyright and making them freely available.

ManyBooks.net - This site has a lot of overlap with Project Gutenberg, but also has some newer works that have been made available, such as Charles Stross's Accelerando.

Fictionwise - Although heavy on the Science Fiction and Fantasy, has a lot of offerings in other genres as well. Reasonably priced and DRM-free.

Cory Doctorow - Cory was one of the first authors to make a point of offering all of his works not only DRM-free but free of charge in e-book formats from his Web site. But you know, when the book he co-authored with Charles Stross Rapture of the Nerds came out recently I went to the Google Play store and bought it.

DriveThru Fiction - An interesting site that also has Comics and RPG games available.

Apress - A publisher of technical books that also offers reduced-price e-books if you have already purchased the print title. This is something I'd like to see more of.

Audiobooks

This is where there is still a big disappointment. Audible, which is by any measure the clear leader here, insists on DRM on all of their books, which is why I refuse to get an account. Audible is now owned by Amazon, which sells music tracks as MP3 files without DRM, so there was hope when they bought Audible that we could get DRM-free audiobooks, but that was not the case. Fortunately, there are alternatives.

eMusic - This is the same site I mentioned above for DRM-free musci tracks. They also offer a subscription plan for audiobboks, $10 a month gets you one book. Selection is not as good as Audible, but their list is growing all of the time and I have had no trouble finding books there that interest me. I recently listened to Walter Isaacson's biogrpahy of Albert Einstein through a book I bought here.

Podiobooks - This site offers audiobooks in serialized form, much like podcasts offer you a file every week. Heavy on the Science Fiction and Fantasy at this point, but worth checking out. Scott Sigler and J.C. Hutchins are both available here, for instance.

Scott Sigler - Scott used free content to get his name out, but still offers free audio versions on his web site even though he now has a publisher.

Cory Doctorow - Cory in addition to offering free ebooks also offers audiobooks that are DRM-free on a "name your own price" basis. Among the readers on his books are Neil Gaiman, Wil Wheaton, Spider Robinson, and Leo Laporte. He even sells files and CDs in Ogg format if you prefer to get your files that way. Due seriously gets freedom, but if you know anything about Cory Doctorow you know that.

Richard Stallman

Richard Matthew Stallman (born March 16, 1953), often shortened to rms, is an American software freedom activist and computer programmer. In September 1983, he launched the GNU Project to create a free Unix-like operating system, and he has been the project's lead architect and organizer. With the launch of the GNU Project, he initiated the free software movement; in October 1985 he founded the Free Software Foundation.
Stallman pioneered the concept of copyleft, and he is the main author of several copyleft licenses including the GNU General Public License, the most widely used free software license. Since the mid-1990s, Stallman has spent most of his time advocating for free software, as well as campaigning against software patents, digital rights management, and what he sees as excessive extension of copyright laws. Stallman has also developed a number of pieces of widely used software, including the original Emacs, the GNU Compiler Collection, the GNU Debugger, and various tools in the GNU coreutils. He co-founded the League for Programming Freedom in 1989.

The Free Software Definition

A program is free software if the program's users have the four essential freedoms:

The freedom to run the program, for any purpose (freedom 0).

The freedom to study how the program works, and change it so it does your computing as you wish (freedom 1). Access to the source code is a precondition for this.

The freedom to redistribute copies so you can help your neighbor (freedom 2).

The freedom to distribute copies of your modified versions to others (freedom 3). By doing this you can give the whole community a chance to benefit from your changes. Access to the source code is a precondition for this.

Free as in Freedom

Free as in Freedom oggcast - http://faif.us
Free as in Freedom is a bi-weekly oggcast, hosted and presented by Bradley M. Kuhn and Karen Sandler. The discussion includes legal, policy, and many other issues in the Free, Libre, and Open Source Software (FLOSS) world. Occasionally, guests join Bradley and Karen to discuss various topics regarding FLOSS.
You can email feedback on the show to oggcast@faif.us, or join bkuhn and other listeners in our IRC channel, #faif on irc.freenode.net.

Free Software Foundation

The Free Software Foundation (FSF) is a non-profit corporation founded by Richard Stallman on 4 October 1985 to support the free software movement, a copyleft-based movement which aims to promote the universal freedom to create, distribute and modify computer software. The FSF is incorporated in Massachusetts, USA.
From its founding until the mid-1990s, FSF's funds were mostly used to employ software developers to write free software for the GNU Project. Since the mid-1990s, the FSF's employees and volunteers have mostly worked on legal and structural issues for the free software movement and the free software community.
Consistent with its goals, only free software is used on FSF's computers.